I spent a lot of time struggling with creating the central object - the segmenting circle. I wanted it to have certain properties so that when I moved it around, it would naturally segment itself. When I finally managed that to my satisfaction, it was just a question of using the tool I had created in an interesting enough way. I wish I could have figured out how to make the balls actually fragment more than I managed, but overall I like how the basic interaction creates interesting illusions in the eye.